max bittkerandClaude Fable 5.1
db1f30e1c1
Engine
- World.processLogins takeover: closeModal() before save(), so items parked in
temp invs (tradeoffer/dueloffer/duelwinnings/partyroom_tempinv) return to the
pack before the snapshot. Logging in from a second client mid-trade deleted
the offer and left the partner's screen stuck; reproduced locally before and
after.
- Web server proxies /state/:bot, /chat/:bot, POST /say/:bot, POST /dm/:bot to
the gateway (cli.ts / chat.ts HTTP fast paths 404'd on deployments that
front the gateway through the engine web port).
SDK
- interactNpc/useItemOnNpc/talk path re-find an entity target by server index
after walking (ActionHelpers.refindNpc) instead of by name, so a chosen
fishing spot is not swapped for the nearest same-named one.
- runner: log a failed initial connect and tear down the orphan BotSDK (its
reconnect timers kept the process alive as a zombie); connect race 30s -> 90s
to cover a cold browser launch; browserLaunchTimeout default 30000 as documented.
- mcp/api: bot.env repo-root fallback was one directory short.
- cli.ts honours GATEWAY_URL from bot.env like the runner does.
- shortestNameMatch falls back to a substring match when a literal name with
regex metacharacters ("Serum 207 (1)") matches nothing as a regex (+test).
- eatFood accepts Drink; openBank skips "Closed bank booth" and prefers a booth
with a Bank/Use op; attack re-finds a bare {index} handle instead of throwing;
depositItem(number) returns an invalid-target result instead of a TypeError.
- ActionDispatchError sets its name via defineProperty (hosts that freeze
Error.prototype made the assignment throw from ws.onclose).
Webclient
- Client.say() routes '::' to CLIENT_CHEAT like the keyboard path and the lite
client, instead of speaking cheats aloud as public chat.
- Client.isBankOpen() returns false when no main modal is open (component 2006
linkObjType is never cleared, so state.bank.isOpen stuck true all session).
- acceptCharacterDesign (lite + browser) prefers the CC_ACCEPT_DESIGN button
inside the open modal; other kits carry the same clientcode with no trigger.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
RS-SDK
Research-oriented starter kit for runescape-style bots, including a typescript sdk, agent documentation and bindings, and a server emulator. Works out of the box - tell it what to automate!
Build and operate bots within a complex economic role-playing MMO. You can automate the game, level an account to all 99s, and experiment with agentic development techniques within a safe, bot-only setting.
The goals of this project are to provide a rich testing environment for goal-directed program synthesis techniques (Ralph loops, etc), and to facilitate research into collaboration and competition between agents.
There is currently a leaderboard for bots running on the demo server, with rankings based on highest total level per lowest account playtime.
See the benchmark comparing models for evaluation results across different LLMs.
Note
RS-SDK is a fork of the LostCity engine/client, an amazing project without which rs-sdk would not be possible. Find their code here or read their history and ethos
Getting Started:
git clone https://github.com/MaxBittker/rs-sdk.git
Out of the box, you can connect to the provided demo server, choose a name that is not already taken!
With claude code:
bun install
claude "start a new bot with name: {username}"
Manually:
bun install
bun bots/create-bot.ts {username}
bun bots/{username}/script.ts
Agent API and knowledge
The exact generated API surface is documented in
sdk/API.md. High-level bot.* methods attempt to observe
method-specific game effects; low-level sdk.send* methods confirm
browser-client dispatch and do not prove the server applied the effect.
MCP execute_code snippets receive bot and sdk globals. Standalone files
under bots/<name>/ instead use runScript(async ({ bot, sdk }) => { ... });
see learnings/README.md for copyable examples.
The current executor evaluates JavaScript-compatible async bodies directly, so
use the TypeScript API reference for type information but omit type-only syntax
from an execute_code body.
Chat is shown by default. Note that seeing other players' chat exposes the bot to scamming and prompt-injection attempts; opt out with SHOW_CHAT=false in the bot.env file (or bun bots/create-bot.ts <name> --no-chat).
Warning: The demo server is offered as a convenience, and we do not guarantee uptime or data persistence. Hold your accounts lightly, and consider hosting your own server instance. Please do not manually play on the demo server.
Gameplay Modifications
This server has a few modifications from the original game to make development and bot testing easier:
- Faster leveling - The XP curve is accelerated and less steep.
- Infinite run energy - Players never run out of energy
- No random events - Anti-botting random events are disabled
Architecture:
rs-sdk runs against an enhanced web-based client (botclient) which connects to the LostCity 2004scape server emulator.
There is a gateway server which accepts connections from botclient and SDK instances, and forwards messages between them based on username.
Once connected to the gateway, the botclient relays game state to the SDK and
dispatches low-level actions such as sendWalk(x, z) from the SDK. Dispatch
success is not confirmation that the game server applied the intended effect.
This means that the SDK can't talk directly to the game server, but must go through the botclient. It will attempt to launch the botclient on startup if one is not already running.
You don't need to run the gateway/botclient in order to run automations against the demo server, but you may choose to if you are fixing bugs or adding features to the rs-sdk project
Running the server locally
Running the server locally has many advantages, primary being the ability to set a high tickrate.
You can set tickrate in server/engine/.env via the NODE_TICKRATE variable (default is 400ms, try 200ms or 30ms for faster gameplay, especially useful for headless testing). You can also change it at runtime with the in-game ::speed <ms> command (minimum 20ms, doesn't persist across restarts).
The chat profanity filter can be disabled with NODE_PROFANITY_FILTER=false (default on). The server censors chat before broadcasting and injects the setting into the browser client; headless lite runners have no config channel from the server, so also set PROFANITY_FILTER=false in the bot's bot.env (or process env) to stop their local re-censoring.
You want all three of these running:
# Game engine
cd server/engine && bun run start
# Web client bundler
cd server/webclient && bun run watch
# Gateway (bridges SDK <-> bot client)
cd server/gateway && bun run gateway
The gateway listens on ws://localhost:7780 by default (configurable via AGENT_PORT env var).
Development checks
Install the root and webclient dependencies, then run the same checks as CI:
bun install --frozen-lockfile
(cd server/webclient && bun install --frozen-lockfile)
bun run check
bun run docs:api regenerates the API reference. CI fails when that document
does not match the public TypeScript class surface.
2. Connect a bot to the local gateway
The SERVER variable in bot.env controls where the bot connects. To use your local gateway, leave SERVER blank:
BOT_USERNAME=mybot
PASSWORD=test
SERVER=
SHOW_CHAT=true
When SERVER is empty, all connection paths (scripts, CLI) default to ws://localhost:7780.
When SERVER is set to a hostname (e.g. rs-sdk-demo.fly.dev), they connect to wss://{SERVER}/gateway instead.
Disclaimer
This is a free, open-source, community-run project.
The goal is strictly education and scientific research.
LostCity Server was written from scratch after many hours of research and peer review. Everything you see is completely and transparently open source.
We have not been endorsed by, authorized by, or officially communicated with Jagex Ltd. on our efforts here.
You cannot play Old School RuneScape here, buy RuneScape gold, or access any of the official game's services! Bots developed here will not work on the official game servers.
License
This project is licensed under the MIT License. See the LICENSE file for details.